Is this a noun clause?

[Muyong26]

Dear sir/ madam
I wonder why they use the sentence like this
Should he come, I will let you know.
why they don't use If instead of should
and another is the same type
If you were to cut my hair,how short would you make it?
why they don't use ought instead of were

many thanks for your answer

[Alan]

Hi,

In the sentence 'should he come' is just an alternative way of saying 'if he comes/if he came'. It is used more often in conversation or in writing as a literary form. 'Ought to' means the same roughly as 'should' in the sense of saying what is the right thing to do: 'You ought to pay your taxes/you should pay your taxes.' 'Were to' is quite different and is a subjunctive form: If you were to accept/if you accepted the job, would you be happy?'. In that sentence it is an alternative to the past subjunctive (accepted).

Alan
_________________
English as a Second Language
You can read my ESL story Present Simple

[Muyong26]

Dear Alan
:D thanks for your answer

[Sohrab]

Dear Alan,
In your answer you said that "were to is a subjunctive form." I always thought the whole setting is nothing but an if clause which in turn is equal to an adverbial clause. My understanding of sujunctive is that it functions as an advice whose outcome and result is uncertain. In the sentence,"It's important that he work harder." or in "He requested I pay back my debt." What i'm wondering now is whether the "If you were to cut my hair," has the same sense of meaning.
With my all best wishes,
ssoski